Process for pasteurizing liquids.



O. KRUG.

PROCESS FOR PASTEURIZING LIQUIDS.

APPLICATION FILED BBQ. 12, 1913.

Patented Dec. 1 1914.

l; T L g I m. n t L x T u 1 t n. I I I t I Z I 2 I I 1 .n 2 r 2 I T I lI I I T L 1 I I I 1 I u T I 2 I I Z L I I. I I I I I I T I 1 Z I I H I II I I I Q a 2 HIS ATTORNEY- UNITED STATES PATENT OFFICE.

CARL KRUG, OF FRANKFORT-ON-THE-MAIN, GERMANY.

PROCESS FOR PASTEURIZING LIQUIDS.

Specification of Letters Patent.

PatcntedDec. 1, 1914.

Application filed December 12, 1913. Serial No. 806,208.

air being used as a counter-pressure medium.

When pasteurizing liquids in bottles it is well known to expose thelatter in a box-like casing to the action of steam obtained from pipingin the box. Further, in order to obviate fracture of the bottles inconsequence of the pressure above atmospheric which is produced in themit is well-known to employ compressed air as a counter-pressure mediumand to mix the hot steam with the compressed air. my invention differsfrom this known process in that the compressed air is supplied both whenheating and when cooling the bottles through a system of piping suitablyarranged in the pasteurizing chamber and issues therefrom into the upperpart of the pasteurizing chamber, whereby the compressed air ispreheated during the heating of the pasteurizing chamber by the steamand, after the pasteurization, i. 6. after the steam has been shut offand the closure member of the pasteurizing chamber has been opened,ejects the hot mixture of steam and air out of the pasteurizing chamberand gradually cools the bottles.

The advantages to be obtained by the invention are, firstly, a smallerconsumption of operating agents, because the heat of the steam is morecompletely utilized and the compressed air is gradually heated insidethe pasteurizin chamber by the heat of the steam itself. econdly, theprocess can be rapidly carried out and therefore the pasteurizingapparatus can be efficiently used, because the temperature in theapparatus can be raised relatively rapidly to the desired degree bysupplying the requisite amount of steam and in such manner that thetemperature in the entire casing acts uniformly on the bottles; on theother hand, the process can be accelerated by cooling the bottlessystematicallv without the same be- -ing endangered. Thirdly, theinvention very greatly reduces the number of bottles which are broken,as compared with known The process according to processes, both inconsequence of the uniform pasteurizing temperature which is' guaranteedby the compressed air supplied from the top and, in addition owing tothe gradual cooling due to the compressed air which itself coolsgradually. I

One form of apparatus adapted for carrying my process into practice isdiagrammatic'ally represented by way of example in the accompanyingdrawing, wherein:

Figure 1 is a longitudinal section, Fig. 2

a top plan view of the bottom. and Fig. 3 a

top plan view of the top of the pasteurizing apparatus. V

The pasteurizing apparatus comprises a known box-like casing a having atits front end atightly closing door or doors b for inserting andremoving a wagon or truck a carrying the bottles. The interior of thebox a is heated by steam supplied by means of a system of pipes (l onthe bottom of the box. The feed pipe leading to these pipes is providedoutside the box with a stop cock 2' to be operated by hand and aregulator j in the-form of a known thermostat which operates at apredetermined temperature, e. g. at 7075 C. and automatically closes asecond stop cook or closure member. The outlets for steam in the pipingdfare preferably directed toward the bottom of the box, so that this isheated first.) v A second system of piping e is provided-inside the box,preferably at the two sides, at the rear end wall and at the top theinlet end f of this system is connected to a'compressedair vessel fed byan air compressor. Cold compressed air is supplied by the air-vesselthrough the piping e in which it is heated to the temperature of thesteam (7075 C.) The heated compressed air is forced into thepasteurizing-chamber at the top of the box; the air may flow in eitherthrough a pipe 9 leading into the top of the box, or through the topturn of the pipe which will be provided with suitable outlets. A safetyvalve may be provided in known manner on the pasteurizing box. In thetop of the box a is a blow-off cock I: which is opened when the pressureabove atmospheric in the box is to be let off after the termination ofthe pasteurization.

The apparatus is used as follows :-Steam is first allowed to passthrough the piping d in known manner into the pasteurizing chamber. Thelatter is gradually heated to about 70-75 (3., while the temperature ofthe contents of the bottles does not at once attain this height andtherefore there is no dangerous excess pressure in the bottles. Whilethe temperature of the contents of the bottles gradually rises to thetemperature of the pasteurizing chamber, however, and the pressure inthe bottles also rises, the admission valve of the pipe 7 is opened andsteam is shut oil from the pipe d. The compressed air flows into thepiping e, becomes heated therein and is then supplied from above intothe pasteurizing chamber. After pasteurization has taken place the cockh on the cover of the box is opened. The fresh compressed air which isnow continuously supplied to the piping e drives the hot mixture ofsteam and compressed air out of the pasteurizing chamber into the open;in consequence of the fall of temperature occasioned hereby in thepasteurizing chamber the compressed air is also gradually cooled as itenters the latter, so that the bottles are systematically graduallycooled. The bottles are finally cooled after removing the same into theopen air.

1 claim:

1. A process of pasteurizing liquids in bottles in a closed chamber,consisting in heating the chamber by supplying steam into the same, inshutting off the supply of steam, in supplying compressed air throughand into the top of the chamber while the liquid in the bottles is beingheated by the steam in the chamber. and in then opening an outlet of thechamber, whereby the compressed air' is preheated while the chamber isbeing heated by the steam, subsequently ejecting the hot mixture ofsteam and air out of the chamber and gradually cooling the bottles.

2. A process of pasteurizing liquids in bottles in an inclosed space,said process consisting in heating said inclosed space by indirectcontact and by injecting steam into and toward the bottom of theinclosed space; continuing said heating and injection until thetemperature in the space registers from 70 to 75 (1.; passing compressedair back and forth at the sides, end and top of said space in indirectcontact with the steam whereby the compressed air is heated toapproximately the temperature of the steam; injecting the heatedcompressed air downwardly into the upper part of said space whereby thepressure of the steam and air therein is raised while the pressure inthe bottles is being raised by the heat therein; and establishingcommunication between said space andthe outside air whereby the injectedcompressed air gradually displaces the heated steam and air mixture withcooler air. 7

3. A process of pasteurizing liquids in bottles in an inclosed space,said process consisting in injecting steam in the lower part of saidspace until .the temperature therein is about 70 to 75 0.; passingcompressed air in indirect contact with the steam in the space andinjecting the compresssed air downwardly into the space thereby raisingthe pressure therein; and establishing communication between said spaceand the outside air whereby the said compressed air gradually displacesthe steam and gas mixture in the space.

4. A process of pasteurizing liquids in bottles in an inclosed space,said process consisting in injecting steam in said space until thetemperature therein is raised; passing compressed air in indirectcontact with the steam in the space whereby the air is heated; injectingthe heated compressed air into the space; and finally displacing thesteam and air mixture with the compressed air.

In testimony whereof, I aflix my signature "Witnesses:

CARL Gnuno, J EAN' GRUND.

